This invention relates to an improved reel for a tape cassette. More particularly, this invention relates to an upper reel flange for a tape cassette having a plurality of ribs in a central recessed portion to maintain vertical alignment of the flanges during stacking. Still more particularly, this invention relates to such an improved upper reel flange for a tape cassette wherein the thickness of the reel flange decreases with an increasing radius from a center recessed portion of the reel flange. In addition, this invention relates to a method of stacking such reel flanges in a manufacturing process to maintain true alignment for transfer by a vacuum mechanism.
A number of tape cassettes are known for use in a conventional video tape recorder (VTR). In general, such cassettes include an opening extending along one side of the cassette with a cutout in the bottom of the cassette housing communicating with that opening. A plurality of reels are rotatably mounted within the cassette for receiving magnetic tapes for transfer between the reels. A magnetic tape is guided across the opening so that, when the tape cassette is loaded into a tape cassette holder of the VTR, tape loading pins mounted on a loading ring are inserted into the cutout of the cassette housing behind the tape run. Rotation of the loading ring causes the tape loading pins to engage the tape in the run between the reels, to withdraw the tape from the cassette housing and to wrap the withdrawn tape around the peripheral surface of the guide drum of the VTR. A conventional tape cassette is usually provided with a lid which is movable on the cassette housing between a closed position covering the opening of the housing and an open position to which the lid is moved when the cassette is placed in the cassette holder.
Examples of such cassette mechanisms are shown in U.S. Pat. Nos. 4,405,962; 4,418,373; 4,445,154; 4,449,677; and 4,482,104, all assigned to the assignee of this application. As there shown, the supply reel and the take-up reel each includes a lower reel flange and an upper reel flange. The lower reel flange includes teeth at its periphery to prevent rotation of the reel when the cassette is not in use and to prevent rotation of the supply reel in a manner inconsistent with the take-up reel. The upper reel flanges of each reel generally include a structure for mating with and securing the upper reel flange at its central portion to a coaxial cylindrical projecting portion disposed between the upper reel flange and the lower reel flange. The present invention addresses a problem in manufacturing such cassettes which arises in maintaining the upper reel flange in an aligned stack for transfer by a vacuum mechanism during the manufacturing process.
Accordingly, it is overall object of the present invention to provide an improvement in a tape cassette, particularly of the type used with 8 mm video tape recorders, by providing the upper reel flange with a plurality of ribs formed in the recessed central portion of the upper reel flange so that the cassette reel may be maintained in an aligned fashion in a stack for transfer by a vacuum mechanism.
During the manufacturing process, it is desired to provide a plurality of upper reel flanges in a substantially true vertical alignment on a stacking pin so that a surface of the upper reel flange may be contacted by a vacuum mechanism to transfer the upper reel flange to a subassembly of the video cassette to be secured therein. The problem has arisen in the art in that when the opening in the upper reel flange is maintained at a relatively large dimension compared to the stacking pin to permit easy insertion and withdrawal of the flange over the stacking pin, the opposite sides of the central recessed portions tend to nest one within the other, thus skewing the vertical alignment of the stack. When a stack of upper reel flanges is thus skewed, difficulties may be encountered in grasping the upper reel flange with a vacuum attachment primarily because of the angle at which an extending annular surface of the upper reel flange lies relative to the vacuum attachment.
Accordingly, it is a primary object of this invention to provide an upper reel flange for a video tape cassette which is structured to maintain the vertical and horizontal alignment of the upper cassette reel flange during manufacture and to facilitate its transfer from a stack to a subassembly.
When stacks of upper reel flanges are skewed, a secondary problem may arise. Since such upper reel flanges are generally made from a clear plastic material, such radial movement of one reel flange relative to another in a stack may cause scratching and abrasion which appear to be untidy and, in a worst case, may abraid the shoulder between the recessed central portion and the laterally extending annular flange of an upper reel flange. Such an abrasion of the shoulder may possibly affect the true operation of the flange. Accordingly, it is a secondary object of this invention to overcome the radial slippage between adjacent upper reel flanges when stacked during the manufacturing process by maintaining their true vertical and horizontal alignment during a phase of the manufacturing process.